Featured Research

Bacteria may hold the key for our future. Amid mounting agreement that future clean, "carbon neutral," energy will rely on efficient conversion of the sun's light energy into fuels and electric power, attention is focusing on one of the most ancient groups of organism, the cyanobacteria.

Share This

Anabaena sphaerica belongs to the domain bacteria in the phylum cyanobacteria. Amid mounting agreement that future clean, "carbon-neutral", energy will rely on efficient conversion of the sun's light energy into fuels and electric power, attention is focusing on one of the most ancient groups of organism, the cyanobacteria.

Amid mounting agreement that future clean, "carbon-neutral", energy will rely on efficient conversion of the sun's light energy into fuels and electric power, attention is focusing on one of the most ancient groups of organism, the cyanobacteria.

Related Articles

Dramatic progress has been made over the last decade understanding the fundamental reaction of photosynthesis that evolved in cyanobacteria 3.7 billion years ago, which for the first time used water molecules as a source of electrons to transport energy derived from sunlight, while converting carbon dioxide into oxygen.

The light harvesting systems gave the bacteria their blue ("cyano") colour, and paved the way for plants to evolve by "kidnapping" bacteria to provide their photosynthetic engines, and for animals by liberating oxygen for them to breathe, by splitting water molecules. For humans now there is the tantalising possibility of tweaking the photosynthetic reactions of cyanobacteria to produce fuels we want such as hydrogen, alcohols or even hydrocarbons, rather than carbohydrates.

Progress at the research level has been rapid, boosting prospects of harnessing photosynthesis not just for energy but also for manufacturing valuable compounds for the chemical and biotechnology industries. Such research is running on two tracks, one aimed at genetically engineering real plants and cyanobacteria to yield the products we want, and the other to mimic their processes in artificial photosynthetic systems built with human-made components. Both approaches hold great promise and will be pursued in parallel, as was discussed at a recent workshop focusing on the photosynthetic reaction centres of cyanobacteria, organised by the European Science Foundation (ESF).

A key point noted by Eva Mari Aro, the vice-chair of the ESF conference, was that there is now universal agreement over the ability of photosynthesis to provide large amounts of clean energy in future. While the sustainable options currently pursued such as wind and tidal power will meet some requirements, they will not be able to replace fossil fuels as sources of solid energy for driving engines, nor are they likely to be capable on their own of generating enough electricity for the whole planet.

Meanwhile the current generation of biofuel producing crops generally convert less than 1% of the solar energy they receive to biomass, which means they would displace too much agricultural land used for food production to be viable on a large scale. There is the potential to develop dedicated systems, whether based on cyanobacteria, plants, or artificial components, capable of much higher efficiencies, reaching 10% efficiency of solar energy conversion. This would enable enough energy and fuel to be produced for a large part of the planet's needs without causing significant loss of space for food production.

As Aro pointed out, photosynthesis evolved by cyanobacteria produced all our fossil fuels in the first place. However the rapid consumption of these fossil fuels since the industrial revolution would if continued return atmospheric carbon dioxide towards the levels at the time cyanobacteria evolved, also heating the planet up to the much higher temperatures that prevailed then.

The objective now is to exploit the same reactions so that the remaining fossil fuels can be left in the ground. Among promising contenders discussed at the ESF conference was the idea of an artificial leaf that would simulate not just photosynthesis itself but also the ability of plants to regenerate themselves. This could be important, since the reactions of photosynthesis are destructive, dismantling the protein complexes where they take place, which therefore need regular reconstruction. Under a microscope, chloroplasts, the sub-cellular units where photosynthesis take place, resemble a permanent construction site, and even artificial systems would probably need some form of regenerative capability.

A future aim therefore is to build an artificial leaf-like system comprised of self-assembling nanodevices that are capable of regenerating themselves – just as in real plants or cyanobacteria. "Fundamental breakthroughs in these directions are expected on a time scale of 10 to 20 years and are recognized by the international science community as major milestones on the road to a renewable fuel," said Aro.

Such breakthroughs depend on further progress in understanding the precise structure and mechanisms of photosynthesis, in particular the protein complex known as photosystem II, which breaks down the hydrogen atoms of water into their constituent protons and electrons to carry the energy derived from sunlight onto photosystem I, leading to production of carbohydrates and ultimately also the proteins and fats required by all organisms.

The conference "Molecular Bioenergetics of Cyanobacteria: Towards Systems Biology Level of Understanding" was held on the Costa Brava, Spain during spring 2008.

More Earth & Climate News

Featured Research

Mar. 3, 2015 — Researchers studied quartz from the San Andreas Fault at the microscopic scale, the scale at which earthquake-triggering stresses originate. The results could one day lead to a better understanding ... full story

Mar. 3, 2015 — The 3-D printing scene, a growing favorite of do-it-yourselfers, has spread to the study of plasma physics. With a series of experiments, researchers have found that 3-D printers can be an important ... full story

Mar. 3, 2015 — Researchers have developed a new way of rapidly screening yeasts that could help produce more sustainable biofuels. The new technique could also be a boon in the search for new ways of deriving ... full story

Mar. 3, 2015 — For almost a century, scientists have been puzzled by a process that is crucial to much of the life in Earth's oceans: Why does calcium carbonate, the tough material of seashells and corals, ... full story

Mar. 3, 2015 — Major cities in the UK are falling behind their international counterparts in terms of their use of smart technologies, according to a new study. The research has found that smart cities in the UK, ... full story

Mar. 3, 2015 — To simulate chimp behavior, scientists created a computer model based on equations normally used to describe the movement of atoms and molecules in a confined space. An interdisciplinary research ... full story

Mar. 3, 2015 — Rather than just waiting patiently for any pollinator that comes their way to start the next generation of seeds, some plants appear to recognize the best suitors and 'turn on' to increase the chance ... full story

Mar. 3, 2015 — Methane emissions are strongly reduced in lakes with anoxic bottom waters. But – contrary to what has previously been assumed – methane removal is not always due to archaea or anaerobic bacteria. ... full story

Related Stories

June 30, 2014 — Water splitting is one of the critical reactions that sustain life on Earth, and could be a key to the creation of future fuels. It is a key in the process of photosynthesis, through which plants ... full story

Dec. 3, 2013 — Renewable energy sources such as wind-powered generators can be more reliable and efficient by better controlling the process of getting electricity onto the power grid, according to new ... full story

Apr. 13, 2011 — After years of neglect, scientists and policy makers are focusing more attention on developing technologies needed to make the so-called "green grid" possible, according to a new article. ... full story

Aug. 3, 2010 — By embedding the element selenium in zinc oxide, researchers have made a relatively inexpensive material that could be promising for solar power conversion by making more efficient use of the ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.